Communication apparatus, information processing apparatus, control method, and storage medium

ABSTRACT

A communication apparatus transmits or receives an Extremely High Throughput (EHT) single-user (SU) physical-layer protocol data unit (PPDU), an EHT extended range (ER) SU PPDU, or an EHT multi-user (MU) PPDU. The transmitted or received EHT PPDU includes an EHT signal field (EHT-SIG) which includes a field indicating information regarding semi-orthogonal multiple access (SOMA).

BACKGROUND Field

The present disclosure relates to an apparatus for communicating datathrough wireless communication.

Description of the Related Art

As a wireless local area network (WLAN) standard formulated by theInstitute of Electrical and Electronics Engineers (IEEE), there is theIEEE 802.11 standard series.

US Patent Publication Application No. US2018/0084584 discusses atechnique for executing wireless communication using orthogonalfrequency-division multiple access (OFDMA) in the IEEE 802.11axstandard. In the IEEE 802.11ax standard, high peak throughput isachieved by executing wireless communication using OFDMA.

An Extremely High Throughput (EHT) study group of the IEEE isformulating the IEEE 802.11be standard, which is a next-generation WLANcommunication standard. The IEEE 802.11be standard considers theintroduction of a new multiple access method to improve the throughput.

The IEEE 802.11be standard considers the introduction of semi-orthogonalmultiple access (SOMA). A communication apparatus that transmits data toa plurality of other communication apparatuses can multiplex the data tobe transmitted to the plurality of other communication apparatuses usingSOMA and simultaneously transmit the multiplexed data. In theconventional IEEE 802.11 series standards, however, SOMA has not beenused, and therefore, information regarding SOMA cannot be communicatedto apparatuses using the conventional IEEE 802.11 series standards.Thus, a communication apparatus that receives data multiplexed usingSOMA cannot acquire information regarding SOMA and therefore cannotacquire the received data multiplexed using SOMA, where thecommunication apparatus is using a conventional IEEE 802.11 seriesstandard.

SUMMARY

The present disclosure is directed to a technique in which atransmitting communication apparatus that communicates usingsemi-orthogonal multiple access (SOMA) communicates informationregarding SOMA, whereby a receiving communication apparatus thatreceives a signal in which SOMA is used can acquire the received datawhich has been multiplexed using SOMA.

According to one embodiment of the present disclosure, a communicationapparatus includes a generation unit configured to generate an ExtremelyHigh Throughput (EHT) physical-layer protocol data unit (PPDU), whereinthe generated EHT PPDU is one of an EHT single-user (SU) PPDU, an EHTextended range (ER) SU PPDU, or an EHT multi-user (MU) PPDU, and atransmission unit configured to transmit the EHT PPDU generated by thegeneration unit. The generated EHT PPDU includes a legacy short trainingfield (L-STF), a legacy long training field (L-LTF) configured to becommunicated after the L-STF, a legacy signal field (L-SIG) configuredto be communicated after the L-LTF, an EHT signal field (EHT-SIG)configured to be communicated after the L-SIG and including a fieldindicating information regarding semi-orthogonal multiple access (SOMA),an EHT short training field (EHT-STF) configured to be communicatedafter the EHT-SIG, and an EHT long training field (EHT-LTF) configuredto be communicated after the EHT-STF.

According to another embodiment of the present disclosure, acommunication apparatus includes a reception unit configured to receivean Extremely High Throughput (EHT) physical-layer protocol data unit(PPDU), wherein the received EHT PPDU is one of an EHT single-user (SU)PPDU, an EHT extended range (ER) SU PPDU, or an EHT multi-user (MU)PPDU, and a communication unit configured to execute communication basedon information regarding semi-orthogonal multiple access (SOMA) receivedby the reception unit. The received EHT PPDU includes a legacy shorttraining field (L-STF), a legacy long training field (L-LTF) configuredto be communicated after the L-STF, a legacy signal field (L-SIG)configured to be communicated after the L-LTF, an EHT signal field(EHT-SIG) configured to be communicated after the L-SIG and including afield indicating information regarding SOMA, an EHT short training field(EHT-STF) configured to be communicated after the EHT-SIG, and an EHTlong training field (EHT-LTF) configured to be communicated after theEHT-STF.

Further features will become apparent from the following description ofexemplary embodiments with reference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating a configuration of a network that acommunication apparatus joins in according to one embodiment.

FIG. 2 is a diagram illustrating a hardware configuration of acommunication apparatus according to one embodiment.

FIG. 3 is a diagram illustrating an example of a physical layer (PHY)frame configuration of an Extremely High Throughput (EHT) single-user(SU) physical-layer protocol data unit (PPDU) transmitted from orreceived by a communication apparatus according to one embodiment.

FIG. 4 is a diagram illustrating an example of a physical-layer (PHY)frame configuration of an EHT extended range (ER) SU PPDU transmittedfrom or received by a communication apparatus according to oneembodiment.

FIG. 5 is a diagram illustrating an example of a PHY frame configurationof an EHT multi-user (MU) PPDU transmitted from or received by acommunication apparatus according to one embodiment.

FIG. 6 is a flowchart illustrating processing executed when acommunication apparatus transmits a PPDU according to one embodiment.

FIG. 7 is a flowchart illustrating processing executed when acommunication apparatus receives the PPDU according to one embodiment.

DESCRIPTION OF THE EMBODIMENTS

Exemplary embodiments will be described in detail below with referenceto the attached drawings. The configurations illustrated in thefollowing exemplary embodiments are merely examples, and the presentdisclosure is not limited to the illustrated configurations.

FIG. 1 illustrates the configuration of a network 101 that acommunication apparatus 102 joins in. Communication apparatuses 103 to105 are stations (STAs) having functions of joining in the network 101.The communication apparatus 102 is an access point (an AP) having afunction of constructing the network 101. Each communication apparatusis compatible with the Institute of Electrical and Electronics Engineers(IEEE) 802.11be standard being formulated by an Extremely HighThroughput (EHT) study group and can execute wireless communicationcompliant with the IEEE 802.11be standard via the network 101. Eachcommunication apparatus can communicate in the 2.4 GHz, 5 GHz, and 6 GHzfrequency bands. Each communication apparatus can communicate using 20MHz, 40 MHz, 80 MHz, 160 MHz, and 320 MHz bandwidths.

In the present exemplary embodiment, semi-orthogonal multiple access(SOMA) can be used to transmit and receive data between the AP 102 andthe STAs 103 to 105. In communication using SOMA, a plurality ofindependent signals appropriately allocated different power levels istransmitted in parallel at the same time using a common frequencychannel. These signals are not orthogonal to each other. Ifcommunication is carried out using SOMA, a plurality of signals can besimultaneously transmitted using a common frequency channel. Thus, awireless resource can be utilized in an effective way, and thethroughput of the entirety of the system can be improved.

A communication apparatus that receives a signal with largertransmission power among signals transmitted using SOMA can process, asnoise, signals with smaller transmission power transmitted to othercommunication apparatuses and therefore can receive data similarly to anormal reception process. On the other hand, a communication apparatusthat receives a signal with the smaller transmission power among signalstransmitted using SOMA performs a combined constellation process andthereby can acquire data addressed to the communication apparatus. Thecombined constellation process will be described in detail withreference to table 5.

As a technique for multiplexing a plurality of non-orthogonal signalsand transmitting the multiplexed signals, there is a technique termednon-orthogonal multiple access (NOMA). Also in NOMA, similarly to SOMA,a communication apparatus that receives a signal with largertransmission power can process, as noise, signals with smallertransmission power transmitted to other communication apparatuses andtherefore can receive data similarly to a normal reception process. Onthe other hand, a communication apparatus that receives a signal withsmaller transmission power executes a process termed SuccessiveInterference Cancellation (SIC), thereby extracting data addressed tothe communication apparatus. The communication apparatus that executesthe SIC process regards signals including both a signal addressed toitself and signals addressed to other communication apparatuses assignals addressed to the other communication apparatuses (i.e., regardsthe signal addressed to itself as noise) and demodulates the signals.Then, the communication apparatus excludes the signals addressed to theother communication apparatuses from the signals including both thesignal addressed to itself and the signals addressed to the othercommunication apparatuses and thereby can acquire the data addressed toitself. In NOMA, unlike SOMA, a communication apparatus that receives asignal with smaller transmission power needs to demodulate also signalsaddressed to other communication apparatuses. Thus, the process iscumbersome.

In the above description, the communication apparatuses 102 to 105 arecompatible with the IEEE 802.11be standard. In addition to the IEEE802.11be standard, the communication apparatuses 102 to 105 may also becompatible with a legacy standard that is a standard before the IEEE802.11be standard. Specifically, the communication apparatuses 102 to105 may be compatible with at least any one of the IEEE802.11a/b/g/n/ac/ax standards. In addition to the IEEE 802.11 seriesstandards, the communication apparatuses 102 to 105 may also becompatible with other communication standards such as Bluetooth(registered trademark), near-field communication (NFC), ultra-wideband(UWB), ZigBee, or MultiBand OFDM Alliance (MBOA). UWB includes WirelessUniversal Serial Bus (USB), Wireless 1394, and WiNET. In addition to theIEEE 802.11 series standards, the communication apparatuses 102 to 105may also be compatible with standards such as the Wi-Fi Direct standardformulated by the Wi-Fi Alliance. The communication apparatuses 102 to105 may also be compatible with a wired communication standard for awired local area network (LAN).

Specific examples of the communication apparatus 102 include a wirelessLAN router and a personal computer (PC). The present disclosure,however, is not limited to these examples. Specific examples of thecommunication apparatuses 103 to 105 include a camera, a tablet, asmartphone, a PC, a mobile phone, and a video camera. The presentdisclosure, however, is not limited to these examples.

Although FIG. 1 illustrates a network including a single AP and threeSTAs as an example, the numbers of APs and STAs are not limited to thesenumbers. In a case where STAs perform communication with each other bysimilarly using SOMA, an AP does not need to exist in the network. Forexample, in a case where the communication apparatuses 103 to 105 arecompliant with the Wi-Fi Direct standard, any one of the communicationapparatuses 103 to 105 may operate as a group owner compliant with theWi-Fi Direct standard. Among the communication apparatuses 103 to 105,the remaining communication apparatuses that are not the group owner canoperate as clients compliant with the Wi-Fi Direct standard, whereby thecommunication apparatuses 103 to 105 can achieve communication withoutan AP.

FIG. 2 illustrates a hardware configuration of the communicationapparatus 102 according to the present disclosure. The communicationapparatus 102 includes a storage unit 201, a control unit 202, afunction unit 203, an input unit 204, an output unit 205, acommunication unit 206, and an antenna 207.

The storage unit 201 includes one or more memories such as a read-onlymemory (ROM) and a random-access memory (RAM) and stores computerprograms for performing various operations described below, and varioustypes of information such as communication parameters for wirelesscommunication. As the storage unit 201, as well as the memories such asthe ROM and the RAM, a storage medium such as a flexible disk, a harddisk, an optical disc, a magneto-optical disc, a Compact Disc Read-OnlyMemory (CD-ROM), a Compact Disc Recordable (CD-R), a magnetic tape, anon-volatile memory card, or a digital versatile disc (DVD) may be used.

The control unit 202 includes one or more processors such as a centralprocessing unit (CPU) and a microprocessor unit (MPU) and controls theentirety of the communication apparatus 102 by executing a computerprogram stored in the storage unit 201. The control unit 202 may includean application-specific integrated circuit (ASIC), a digital signalprocessor (DSP), or a field-programmable gate array (FPGA) in additionto or instead of the CPU or the MPU. The control unit 202 may controlthe entirety of the communication apparatus 102 by the cooperationbetween a computer program stored in the storage unit 201 and anoperating system (OS). The control unit 202 generates data and a signalto be transmitted in communication with another communication apparatus.Alternatively, the control unit 202 may include a plurality ofprocessors such as multi-core processors and control the entirety of thecommunication apparatus 102 using the plurality of processors.

The control unit 202 controls the function unit 203 to execute apredetermined process such as capturing of an image, printing, orprojection. The function unit 203 is hardware for the apparatus toexecute the predetermined process.

The input unit 204 receives various operations from a user. The outputunit 205 provides various outputs to the user. In this regard, an outputprovided by the output unit 205 may be at least one of, for example,display on a screen, the output of a sound from a loudspeaker, andvibration output. Both the input unit 204 and the output unit 205 may berealized by a single module such as a touch panel. Each of the inputunit 204 and the output unit 205 may be integrated with or separate fromthe communication apparatus 103.

The communication unit 206 controls wireless communication compliantwith the IEEE 802.11be standard. In addition to the IEEE 802.11bestandard, the communication unit 206 may also control wirelesscommunication compliant with other IEEE 802.11 series standards, orcontrol wired communication via a wired LAN. The communication unit 206is a wireless chip and may itself include one or more processors ormemories as an information processing apparatus. The communication unit206 controls the antenna 207 to transmit and receive a wireless signalfor wireless communication generated by the control unit 202. Thecommunication apparatus 102 communicates with another communicationapparatus via the communication unit 206 to receive and transmit acontent such as image data, document data, or video data therebetween.

The antenna 207 is an antenna capable of transmitting and receiving asignal by using at least any of, for example, the 2.4 GHz, 5 GHz, and 6GHz frequency bands. The frequency bands (and the combinations of thefrequency bands) with which the antenna 207 is compatible are notlimited to any particular frequency. The antenna 207 may be a singleantenna, or may include two or more antennas to transmit and receivedata when multiple-input and multiple-output (MIMO) communication isperformed. In a case where the MIMO communication is executed, thecommunication apparatus 102 assigns the plurality of antennas torespective partner apparatuses or antennas included in the partnerapparatuses and simultaneously transmits radio waves from the antennas,and thereby can realize simultaneous communication with the plurality ofpartner apparatuses or antennas. Alternatively, the antenna 207 mayinclude, for example, two or more antennas compatible with communicationin different frequency bands. The antenna 207 and the communication unit206 may be configured as separate components, or may be configured as aunit of a single module.

The communication apparatuses 103 to 105 also have hardwareconfigurations similar to that of the communication apparatus 102.

FIGS. 3 to 5 each illustrate an example of a configuration of a wirelessframe (a physical-layer protocol data unit (PPDU)) transmitted from orreceived by the communication apparatus 102. FIG. 3 illustrates anexample of a physical-layer (PHY) frame configuration of an EHTsingle-user (SU) PPDU for single-user communication. FIG. 4 illustratesan example of a PHY frame configuration of an EHT extended range (ER) SUPPDU for long-distance transmission. The EHT ER SU PPDU is used in acase where communication in an extended communication range is performedbetween an AP and a single STA. FIG. 5 illustrates an example of a PHYframe configuration of an EHT multi-user (MU) PPDU for multi-usercommunication.

Each PPDU includes a short training field (STF), a long training field(LTF), and a signal field (SIG). As illustrated in FIG. 3, a beginningportion of the EHT SU PPDU includes a legacy short training field(L-STF) 301, a legacy long training field (L-LTF) 302, and a legacysignal field (L-SIG) 303 for ensuring backward compatibility with theIEEE 802.11a/b/g/n/ax standards as legacy standards. Similarly, thePPDUs illustrated in FIGS. 4 and 5 also include L-STFs 401 and 501,L-LTFs 402 and 502, and L-SIGs 403 and 503. In each PPDU, the L-LTF isarranged to be communicated immediately after the L-STF, and the L-SIGis arranged to be communicated immediately after the L-LTF.

In each of the frame configurations illustrated in FIGS. 3 to 5, arepeated legacy signal field (RL-SIG) 304, 404, or 504 arranged to becommunicated immediately after the L-SIG is included in the PPDU. TheRL-SIG field repeatedly includes the content of the L-SIG. The RL-SIG isincluded so that a communication apparatus that receives the PPDU canrecognize that the PPDU is compliant with the IEEE 802.11ax standard orlater. Thus, the RL-SIG may be omitted in a PPDU compliant with the IEEE802.11be standard. Alternatively, in a PPDU compliant with the IEEE802.11be standard, a field that allows a reception apparatus torecognize that the PPDU is compliant with the IEEE 802.11be standard maybe newly provided instead of the RL-SIG.

The L-STF 301 is used to detect a PHY frame signal, perform automaticgain control (AGC), or detect a timing. The L-LTF 302 is used tosynchronize frequencies and times with high accuracy or acquire channelstate information (CSI). The L-SIG 303 is used to transmit controlinformation including information regarding a physical layer data rate,a modulation and coding scheme (MCS), and a PHY frame length. A legacydevice (a non-EHT device) that is not compliant with the IEEE 802.11bestandard and is compliant with the IEEE 802.11a/b/g/n/ax standards candecode the L-STF 301, the L-LTF 302, and the L-SIG 303 (legacy fields).

Each PPDU further includes an EHT-SIG that is arranged to becommunicated immediately after the RL-SIG and is used to communicatecontrol information for communication compliant with the IEEE 802.11bestandard. The EHT SU PPDU illustrated in FIG. 3 includes EHT-SIG-A 305,and the EHT ER SU PPDU illustrated in FIG. 4 includes EHT-SIG-A 405. TheEHT MU PPDU illustrated in FIG. 5 includes EHT-SIG-A 505 and EHT-SIG-B506. Each EHT-SIG field includes information necessary for a process forreceiving the EHT PPDU.

Each PPDU also includes an STF (an EHT-STF 306, 406, or 507) and LTFs(EHT-LTFs 307, 407, or 508) for communication compliant with the IEEE802.11be standard. The EHT-STF is arranged to be communicatedimmediately after the EHT-SIG, and the EHT-LTFs are arranged to becommunicated immediately after the EHT-STF.

Each PPDU includes a data field 308, 408, or 509 and a packet extensionfield 309, 409, or 510 after these fields for control. In each PPDU, thefields from the L-STF to the EHT-LTFs are termed a “PHY preamble”. Thefields of the PPDUs do not necessarily need to be arranged in the ordersillustrated in FIGS. 3 to 5, and a new field not illustrated in FIGS. 3to 5 may be included.

FIGS. 3 to 5 each illustrate as an example a PPDU capable of ensuringbackward compatibility. If, however, it is not necessary to ensure thebackward compatibility, for example, the legacy fields may be omitted.In this case, for example, the EHT-STF and the EHT-LTFs may be includedat the beginning of the PPDU instead of the L-STF and the L-LTF toestablish synchronization. In this case, at least one of the EHT-STF andthe plurality of EHT-LTFs arranged after the EHT-SIG field in the PPDUmay be omitted.

As illustrated in tables 1 and 2, the EHT-SIG-A 305 and the EHT-SIG-A405 included in the EHT SU PPDU and the EHT ER SU PPDU, respectively,each include EHT-SIG-A1 and EHT-SIG-A2 indicating information necessaryto receive the PPDU. In the present exemplary embodiment, a “SOMA”sub-field indicating whether SOMA is used in the transmission of dataincluded in the data field in the PPDU is included in at least one ofthe EHT-SIG-A1 and the EHT-SIG-A2.

If the SOMA sub-field is included in the EHT-SIG-A1, the SOMA sub-fieldmay not be included in the EHT-SIG-A2. If the SOMA sub-field is includedin the EHT-SIG-A2, the SOMA sub-field may not be included in theEHT-SIG-A1. Alternatively, the SOMA sub-field may be included in boththe EHT-SIG-A and the EHT-SIG-A2.

As illustrated in tables 3 and 4, the EHT-SIG-A 505 of the EHT MU PPDUin FIG. 5 includes EHT-SIG-A1 and EHT-SIG-A2 indicating informationnecessary to receive the PPDU. In the EHT MU PPDU according to thepresent exemplary embodiment, a SOMA sub-field as described above isincluded in the EHT-SIG-A2. Alternatively, also in the EHT MU PPDU, theSOMA sub-field may be included in the EHT-SIG-A, or may be included inboth the EHT-SIG-A1 and the EHT-SIG-A2.

In the present exemplary embodiment, if SOMA is used to transmit data, 1is set to the SOMA sub-field. If SOMA is not used, 0 is set to the SOMAsub-field. This is, however, merely an example. Alternatively, if SOMAis used to transmit data, 0 may be set to the SOMA sub-field. If SOMA isnot used, 1 may be set to the SOMA sub-field. The present disclosure isnot limited to these examples. The SOMA sub-field only needs to includeinformation that allows an apparatus that receives the PPDU to recognizethat SOMA is used to transmit data included in the PPDU.

If a value indicating that SOMA is used is set to the SOMA sub-field,data included in the data field in the same PPDU is multiplexed by usingSOMA. If, on the other hand, a value indicating that SOMA is not used isset to the SOMA sub-field, data included in the data field in the samePPDU is not multiplexed by using SOMA.

Consequently, a communication apparatus that receives the PPDU includingthe SOMA sub-field can recognize that it is necessary to perform areception process compatible with SOMA as a process for receiving thePPDU. Thus, the communication apparatus can appropriately determinewhether to perform the reception process compatible with SOMA.

The configurations of frames illustrated in tables 1 to 4 are merelyexamples, and other configurations may be used. For example, in each ofthe EHT SU PPDU and the EHT ER SU PPDU, notification of the informationregarding SOMA may be given at a position other than the fifteenth bitof the EHT-SIG-A1 field or the EHT-SIG-A2 field. Similarly, in the EHTMU PPDU, notification of the information regarding SOMA may be given ata position other than the eighth bit of the EHT-SIG-A2 field. At leastone of the names or the contents of fields illustrated in tables 1 to 4may be different from that illustrated in tables 1 to 4.

TABLE 1 Bit Number Position Sub-Field of Bits Description EHT- B0 Format1 To distinguish PPDU from EHT TB PPDU, SIG- 1 if “EHT PPDU and EHT ERPPDU” A1 B1 Beam Change 1 1 if pre-EHT of PPDU is arranged in differentspace from first symbol of EHT- LTF, 0 if similarly mapped B2 UL/DL 1Indicates whether PPDU is for UL or for DL, and has same value asTXVECTOR UPLINK_FLAG B3-B6 MCS 4 Value of modulation and coding schemeIf EHT SU PPDU: n = 0, 1, 2, . . . , 11 (12 to 15 are reserved) If EHTER SU PPDU and if bandwidth = 0: n = 0, 1, 2 (3 to 15 are reservedareas) If EHT ER SU PPDU and if bandwidth = 1: n = 0 (1 to 15 arereserved areas) in MCS 0 B7 DCM 1 Indicates whether dual carriermodulation is applied to data field If STBC field is 0: 1 (if both DCMand STBC fields are 1, neither is applied) If DCM is not applied: 0B8-B13 BSS Color 6 6 bits for identifying BSS B14 SOMA 1 If multiplexedusing SOMA: 1 If not multiplexed using SOMA: 0 B15-B18 Spatial Reuse 4Indicates whether Spatial Reuse is permitted during transmission of thePPDU Value of Spatial Reuse field encoding illustrated in appendix isset B19-B20 Bandwidth 2 If EHT SU PPDU: 0 if 20 MHz, 1 if 40 MHz, 2 if80 MHz, 3 if 160 MHz (80 + 80 MHz) If EHT ER SU PPDU: 0 if 242-tone RU,1 if upper 106-tone RU in primary 20 MHz B21-B22 GI + LTF Size 2Indicates guard interval period and size of EHT-LTF 0 if 1 × EHT-LTF and0.8 μs GI, 1 if 2 × EHT-LTF and 0.8 μs GI, 2 if 2 × EHT-LTF and 1.6 μsGI, 3 if both DCM and STBC fields are 1 and if 4 × EHT-LTF and 0.8 μsGI, 3 if 4 × EHT- LTF other than above and 3.2 μs GI B23-B25 NSTS and 3Number of space-time streams and Midamble periodicity of midamble forsynchronizing Periodicity frames If Doppler field is 0: number ofspace-time streams is − 1 If Doppler field is 1: B23-B24 are number ofspace-time streams B25 is 0 if midamble periodicity is 10, and 1 if 20

TABLE 2 Bit Number Position Sub-Field of Bits Description EHT- B0-B6TXOP 1 Transmission opportunity SIG- 127 is set if TXOP_DURATION ofTXVECTOR is A2 UNSPECIFIED and period information is not present. Valuesmaller than 127 is set to set NAV if TXOP_DURATION of TXVECTOR issmaller than 512. At this time, if B0 is 0, B1-B6 are FLOOR (truncation)of TXOP_DURATION/8. If B0 is 1, B1-B6 are FLOOR of (TXOP_DURATION −512)/8. B7 Coding 1 0 if binary convolutional code (BCC), 1 if lowdensity parity check (LDPC) B8 LDPC Extra 1 Indicates presence orabsence of extra OFDM Symbol symbol segment for LDPC Segment B9 STBC 1Using space-time block coding (STBC), this field is 1 if DCM is zero,also 1 if neither DCM nor STBC is applied, 0 in other cases B10Beamformed 1 1 if beam forming and steering are applied to waveform, ofSU transmission B11- Pre-FEC 2 0 if pre-FEC padding factor is 4, 1 if itis 1, 2 if it is B12 Padding 2, 3 if it is 3 Factor B13 PE 1Disambiguity field of packet extension Disambiguity B14 SOMA 1 Ifmultiplexed using SOMA: 1 If not multiplexed using SOMA: 0 B15 Doppler 11 if either of following conditions is satisfied Number of OFDM symbolsin data field is greater than “value indicated in midamble periodicity +1” and midamble is present Number of OFDM symbols in data field is lessthan or equal to “value indicated in midamble periodicity + 1”, midambleis not present, and channels change quickly B16- CRC 4 CRC of precedingEHT-SIG-A (total of 42 bits B19 including 26 bits in A1 and 16 bits fromB0 to B15 in A2) fields B20- Tail 6 Area where 0 is set to indicate endto trellis B25 convolutional decoder

TABLE 3 Bit Number Position Sub-Field of Bits Description EHT- B0 UL/DL1 Indicates whether PPDU is for UL or for DL, and SIG- has same value asTXVECTOR UPLINK_FLAG A1 B1-B3 SIGB MCS 3 Indicates MCS of EHT-SIG-Bfield. 0 if MCS is 0, 1 if MCS is 1. 2 if MCS is 2, 3 if MCS is 3, 4 ifMCS is 4, 5 if MCS is 5, 6 and 7 are reserved areas B4 SIGB DCM 1 1 ifEHT-SIG-B field is modulated by DCM B5-B10 BSS Color 6 6 bits foridentifying BSS B11- Spatial Reuse 4 Indicates whether Spatial Reuse ispermitted B14 during transmission of the PPDU Value of Spatial Reusefield encoding illustrated in appendix is set B15- Bandwidth 3 0 if 20MHz, 1 if 40 MHz, 2 if 80 MHz, 3 if 160 B17 MHz (80 + 80 MHz) If SIGBcompression field is 0, 4 if only secondary 20 MHz is puncturing inpreamble puncturing in 80 MHz 5 if two 20 MHz portions of secondary 40MHz are puncturing in preamble puncturing in 80 MHz 6 if only secondary20 MHz is puncturing in preamble puncturing in 160 (or 80 + 80) MHz 7 ifonly secondary 40 MHz is puncturing in preamble puncturing in 160 (or80 + 80) MHz If SIGB field indicates 1, values 4 to 7 mean reservationB18- Number of 4 Indicates number of OFDMA symbols in EHT- B21 EHT-SIG-BSIG-B if SIG compression field is 0. Symbols or If number of OFDMsymbols in EHT-SIG-B is MU-MIMO smaller than 16, this means a numberobtained by Users subtracting 1 from the number of OFDM symbols inEHT-SIG-B. If support capability for the number of OFDM symbols in EHTSIG-B greater than 16 is set to 0 in at least one reception terminal, 15is set to indicate that the number of OFDM symbols in EHT-SIG-B is 16.If support capabilities for the number of OFDM symbols in EHT-SIG-Bgreater than 16 are set to 0 in all reception terminals, and data rateof EHT-SIG-B is smaller than MCS 4 that does not use DCM, 15 is set toindicate that the number of OFDM symbols in EHT SIG-B is greater than orequal to 16. If SIG compression field is 1, this means a number obtainedby subtracting 1 from the number of MU-MIMO users. B22 SIG 1 1 if commonfield is present in EHT-SIG-B Compression B23- GI + LTF Size 2 Indicatesguard interval period and size of EHT- B24 LTF 0 if 4 × EHT-LTF and 0.8μs GI, 1 if 2 × EHT-LTF and 0.8 μs GI, 2 if 2 × EHT-LTF and 1.6 μs GI, 3if 4 × EHT-LTF and 3.2 μs GI B25 Doppler 1 1 if either of followingconditions is satisfied Number of OFDM symbols in data field is greaterthan “value indicated in midamble periodicity + 1” and midamble ispresent Number of OFDM symbols in data field is less than or equal to“value indicated in midamble periodicity + 1”, midamble is not present,and channels change quickly

TABLE 4 Bit Number Position Sub-Field of Bits Description EHT- B0-B6TXOP 1 Transmission opportunity SIG- 127 is set if TXOP_DURATION of A2TXVECTOR is UNSPECIFIED and period information is not present. A valuesmaller than 127 is set to set NAV if TXOP_DURATION of TXVECTOR issmaller than 512. At this time, if B0 is 0, B1-B6 are FLOOR (truncation)of TXOP_DURATION/8. If B0 is 1, B1-B6 are FLOOR of (TXOP_DURATION −512)/8. B7 SOMA 1 If multiplexed using SOMA: 1 If not multiplexed usingSOMA: 0 B8-B10 Number of EHT- 3 Indicates number of EHT-LTFs. LTFSymbols and 0 if 1 × EHT-LTF, Midamble 1 if 2 ×EHT-LTF, Periodicity 2 if4 × EHT-LTF, 3 if 6 × EHT-LTF, 4 if 8 × EHT-LTF If Doppler field is 1,B8-B9 indicate number of EHT-LTF symbols, and B10 indicates midambleperiodicity. B11 LDPC Extra 1 Indicates presence or absence of extraOFDM Symbol Segment symbol segment for LDPC B12 STBC 1 If number ofusers in each Resource Unit (RU) is not greater than 1, 1 is set toindicate that data is coded using STBC. B13- Pre-FEC Padding 2 0 ifpre-FEC padding factor is 4, 1 if it is 1, 2 if B14 Factor it is 2, 3 ifit is 3 B15 PE Disambiguity 1 Disambiguity field of packet extensionB16- CRC 4 CRC of preceding EHT-SIG-A (total of 42 bits B19 including 26bits in A1 and 16 bits from B0 to B15 in A2) fields B20- Tail 6 Areawhere 0 is set to indicate an end to trellis B25 convolutional decoder

In addition to the EHT-SIG-A1 field and the EHT-SIG-A2 field, each PPDUmay include another field. In the present exemplary embodiment, thisfield is referred to as an “EHT-SIG-x field” which is arranged to becommunicated immediately after the EHT-SIG-A1 field or the EHT-SIG-A2field. Alternatively, the EHT-SIG-x field may be arranged to becommunicated immediately after the EHT-SIG-B field. The EHT-SIG-x fieldmay be arranged to be communicated before or after any field in each ofthe PPDU frames illustrated in FIGS. 3 to 5. Yet alternatively, at leastpart of sub-fields included in the EHT-SIG-x field may be included in atleast one of the EHT-SIG-A1 field, the EHT-SIG-A2 field, and theEHT-SIG-B field.

The EHT-SIG-x field can include a sub-field specifying a parameterregarding SOMA. The EHT-SIG-x field may include information other thanthat illustrated in table 5. Table 5 illustrates an example ofinformation stored in the EHT-SIG-x field.

TABLE 5 SOMA Whether multiplexed using SOMA ETH- Destination_0 IDIdentifier of Destination_0 SIG- Super Whether combined constellationprocess is necessary at x Position Destination_0 MCS MCS correspondingto Destination_0 TX power Transmission power to Destination_0 BitPosition of bit allocated to Destination_0 Allocation Destination_1 IDIdentifier of Destination_1 Super Whether combined constellation processis necessary at Position Destination_1 MCS MCS corresponding toDestination_1 TX power Transmission power to Destination_1 Bitallocation Position of bit allocated to Destination_1

The EHT-SIG-x may include the SOMA sub-field illustrated in tables 1 to4. If the SOMA sub-field is included in the EHT-SIG-x, the SOMAsub-field does not need to be included in the EHT-SIG-A1 field or theEHT-SIG-A2 field. Alternatively, the SOMA sub-field may be included inboth the EHT-SIG-x field and the EHT-SIG-A1 field or the EHT-SIG-A2field.

In the present exemplary embodiment, the EHT-SIG-x includes a singlestructured sub-field for each destination of data. Hereinafter, thesub-field will be referred to as a “Destination_y sub-field” (y is aninteger greater than or equal to 0). A single Destination_y sub-fieldmay include a single OFDM symbol, or may include a plurality of OFDMsymbols. The Destination_y sub-field includes at least one of theidentifier (ID) of an STA as a destination, and a field indicatingwhether a combined constellation process is necessary. In addition to orinstead of these fields, the Destination_y sub-field includes at leastone of fields indicating an MCS index to be used, the position of anallocated bit, and transmission power. The MCS is information indicatinga modulation method and a coding rate. In the present exemplaryembodiment, these fields are referred to as an “ID field”, a “superposition field”, an “MCS field”, a “bit allocation field”, and a “TXpower field”.

The ID field is a field indicating information that enablesidentification of an STA. The ID field includes 11 bits, for example. Inthe present exemplary embodiment, the identifier of an STA correspondingto the Destination_y sub-field is stored. As the identifier, forexample, the media access control (MAC) address of the STA is used.Alternatively, instead of the identifier of the STA, a group identifierindicating a group including one or more STAs may be stored in the IDfield.

The superposition field is afield indicating whether the combinedconstellation process needs to be applied. The superposition fieldincludes 1 bit, for example. In the present exemplary embodiment, acommunication apparatus that transmits a PPDU stores 1 in the superposition field, thereby indicating that the combined constellationprocess needs to be used by the STA corresponding to the Destination_ysub-field. A communication apparatus that transmits a PPDU stores 0 inthe super position field to indicate that the combined constellationprocess does not need to be used by the STA corresponding to theDestination_y sub-field. In the present exemplary embodiment, 0 or 1 isstored in the super position field, whereby it is possible to indicatewhether the combined constellation process needs to be applied. Thepresent disclosure, however, is not limited to this example. Acommunication apparatus that transmits the PPDU may indicate, using acharacter string or a code, whether the combined constellation processneeds to be applied.

If SOMA is used, a communication apparatus addressed as the destinationof data which requires larger transmission power can process datarequiring smaller transmission power which is addressed to othercommunication apparatuses as noise, and therefore does not need toexecute the combined constellation process. Thus, the super positionfield may be set to 0 for a communication apparatus addressed as thedestination of data which requires larger transmission power.

The combined constellation process is the process of determining acombined constellation to be applied to primary demodulation, using atleast one of the values of the MCS fields and the TX power fields withina plurality of Destination_sub-fields.

The combined constellation process according to the present exemplaryembodiment is performed as follows. A constellation corresponding to thevalue of the MCS field within a received Destination_0 sub-field can berepresented as {C_(0i)}, which is a set of signal points C_(0i) (i=0, 1,. . . , m−1). Similarly, a constellation corresponding to the value ofthe MCS field within a Destination_1 sub-field can be represented as{C_(1j)} (i=0, 1, . . . , n−1). C_(0i) and C_(1j) are complex numbers,and m and n are the numbers of signal points included in theconstellations. Based on the value of the TX power field within theDestination_0 sub-field and the value of the TX power field within theDestination_1 sub-field, the total transmission power is determined. Theratio of transmission power to the Destination_0 to the determined totaltransmission power is σ. The ratio of transmission power to theDestination_1 to the total transmission power is 1−α. In this case, acombined constellation is expressed as {root(α)C_(0i)+root(1−α)C_(1j)}((i, j) are the combination of values that can be taken by i and j). Theroot(x) represents the square root of x.

For example, if a primary modulation method for the Destination_0 andthe Destination_1 is QPSK, the combined constellation includes 16 signalpoints. If α=0.2, the constellation is normalized by the totaltransmission power, thereby coming to be the same as that obtained by 16quadrature amplitude modulation (QAM) defined by the IEEE 802.11standards.

A communication apparatus that receives the PPDU performs the aboveprocess and thereby can calculate a combined constellation from thepieces of information included in the Destination_0 sub-field and theDestination_1 sub-field. The present disclosure is not limited to thismethod. Alternatively, a communication apparatus that receives the PPDUmay hold a table illustrating the correspondences between the value ofthe MCS field and the value of the TX power field, and a combinedconstellation.

The MCS field is a field indicating an MCS used to transmit data usingSOMA according to the EHT standard. The MCS is information indicatingthe combination of the coding rate and the modulation method of data. Inthe present exemplary embodiment, the MCS field is configured as a fieldof ceil{log₂(the number of types of MCSs that can be used to transmitdata using SOMA)} bits. In this case, ceil(x) is a ceiling function withx as an argument and is a function that returns the smallest integerwhich is greater than or equal to x. If the number of types of MCSs usedto transmit data using SOMA is equal to the number of types of MCSs in acase where SOMA is not used, the number of bits in this field is 4 bitsor more. If, on the other hand, the number of types of MCSs used totransmit data using SOMA is smaller than the number of types of MCSs ina case where SOMA is not used, the number of bits in this field can be 4bits or less.

The present disclosure is not limited to the embodiment. Alternatively,if the MCS included in the MCS field indicates only a primary modulationmethod, the MCS field may be configured as a field indicating a primarymodulation method that can be used to transmit data using SOMA accordingto the IEEE 802.11be standard. The MCS field is a field includingceil(log(the number of types of primary modulation methods that can beused to transmit data using SOMA)) bits at minimum. For example, ifprimary modulation methods are of seven types, namely binary phase-shiftkeying (BPSK), quadrature phase-shift keying (QPSK), 16-QAM, 64-QAM,256-QAM, 1024-QAM, and 4096-QAM, the MCS field is configured as a fieldof 3 bits at minimum. If, on the other hand, primary modulation methodsthat can be used are of only two types, namely BPSK and QPSK, theminimum number of bits in the MCS field is 1 bit. If primary modulationmethods that can be used are of only three types, namely BPSK, QPSK, and16-QAM, the minimum number of bits in the MCS field is 2 bits.

If the value of the super position field indicates that the combinedconstellation process is necessary, the MCS field may be configured as afield indicating a combined constellation. In this case, the combinedconstellation process is performed by a communication apparatus thattransmits the PPDU, and information indicating a combined constellationcorresponding to the processing result is stored in this field. Theminimum number of bits in this field is ceil(log₂(the number of types ofcombined constellations)). For example, if the combined constellationcan be indicated by seven types of constellations defined by the IEEE802.11 standards, the MCS field is configured as a field of 3 bits atminimum. The seven types of constellations defined by the IEEE 802.11standards are BPSK, QPSK, 16-QAM, 64-QAM, 256-QAM, 1024-QAM, and4096-QAM.

The TX power field indicates, in the transmission power of data includedin the data field, transmission power allocated to data for the STA (orthe group of STAs) corresponding to the Destination_y sub-field.Information indicating the transmission power included in the TX powerfield indicates the absolute value of power allocated to the STA or thegroup corresponding to the Destination_y sub-field. Alternatively, theinformation may indicate the ratio or the proportion of transmissionpower used in the combined constellation process. Yet alternatively, thetransmission power may be indicated in another form such as an indexcorresponding to the absolute value of the transmission power. The valueof the transmission power may be indicated by a floating point orinteger constant. The number of bits in the TX power field may be atleast one of 8 bits, 16 bits, 32 bits, and 64 bits. Alternatively, thenumber of bits in the TX power field may be any number of bits. Yetalternatively, the value of the transmission power may be indicated bycoding the transmission power into a fewer number of bits.

In the present exemplary embodiment, if the TX power field indicates theproportion of power allocated to the STA or the group corresponding tothe Destination_y sub-field, the minimum value of the number of bits isceil(log₂(the number of types of proportions)). If the types ofproportions of the transmission power are nine types, namely 0.1+0.1*i(i=0, 1, . . . , 8), the TX power field may be configured as a field of4 bits at minimum.

The bit allocation field is a field indicating the position of a bitallocated to the STA corresponding to the Destination_y sub-field amongbits obtained by demapping the signal points included in the combinedconstellation. Alternatively, the bit allocation field may indicate theposition of a bit allocated to the group of STAs corresponding to theDestination_y sub-field. The bit allocation field includes the number ofbits required to uniquely identify the position of a bit allocated tothe STA or the group of STAs among bits obtained by demapping the signalpoints included in the combined constellation.

The position of a bit allocated to the STA or the group of STAsindicated by the bit allocation field may be indicated in a bitmapformat. In this case, the bit allocation field includes the number ofbits greater than or equal to the maximum multi-valued number that canbe taken by the combined constellation. In the present exemplaryembodiment, in information included in the bit allocation field, theposition of a bit having a value of 1 indicates the position of a bitallocated to the STA. The position of a bit having a value of 0indicates the position of a bit that is not allocated to the STA. Thecorrespondence relationships between values and the allocation are notlimited thereto. Alternatively, 0 may indicate the position of anallocated bit, and 1 may indicate the position of a bit that is notallocated.

For example, if the combined constellation includes a maximum of 4096signal points, the maximum multi-valued number is 12. Thus, the bitallocation field includes 12 bits or more. In this case, if the bitallocation field includes 12 bits, these 12 bits are represented as {b0,b1, . . . , b11}. For example, suppose that the combined constellationincludes 16 signal points (i.e., the multi-valued number is 4), and thepositions of bits allocated to the STA are the second and fourth bits.In this case, the bit allocation field includes information indicating{b0, b1, . . . , b11}={0, 1, 0, 1, 0, . . . , 0}.

Alternatively, the bit allocation field may include, as informationindicating the allocation pattern of the position of an allocated bit,an index corresponding to the pattern. In this case, the bit allocationfield includes ceil(log₂(the number of bit allocation patterns)) bits ormore. For example, if the allocation patterns are of two types, namelyan even-numbered bit and an odd-numbered bit, the bit allocation fieldincludes 1 bit or more.

If the value of the super position field within the correspondingDestination_y sub-field indicates that the combined constellationprocess is not necessary, the value of the bit allocation field may notbe set. In this case, the bit allocation field may be omitted.

The sub-fields included in the EHT-SIG-x field illustrated in thepresent exemplary embodiment are merely examples, and only some of thesesub-fields may be stored in the EHT-SIG-x field or one or a plurality ofDestination_y sub-fields in the EHT-SIG-x field. Alternatively, asub-field indicating another piece of information may be included in theEHT-SIG-x field or one or a plurality of Destination_y sub-fields in theEHT-SIG-x field. Yet alternatively, in a case where a parameterregarding SOMA (a combined constellation or transmission power) isdetermined in advance between a communication apparatus that transmitsthe PPDU and a communication apparatus that receives the PPDU, theEHT-SIG-x field or at least one sub-field in the EHT-SIG-x field may beomitted. The parameter regarding SOMA may be preset in eachcommunication apparatus, or set by the user. If the parameter regardingSOMA is not used in a process for receiving the PPDU, the EHT-SIG-xfield may be omitted. If there is a parameter regarding SOMA that is notused in the process for receiving the PPDU, a corresponding sub-field inthe EHT-SIG-x field may be omitted.

The EHT-SIG-B 506 of the EHT MU PPDU includes a common field and a userblock field including information necessary to receive the PPDU. Theuser block field can store information regarding each user (eachreception apparatus). Thus, the user block field may store informationin the EHT-SIG-x. That is, information regarding each receptionapparatus, such as the ID, the super position, the MCS, the TX power,and the bit allocation, may be transmitted and received using the userblock field. Information in the SOMA sub-field indicating whether SOMAis used may be transmitted and received by including the information inthe common field. Alternatively, the information in the SOMA sub-fieldmay be included in the user block field to indicate whether SOMA is usedwith respect to each reception apparatus.

As described above, the communication apparatus that receives the PPDUconfirms, based on information included in the SOMA sub-field, whetherSOMA is used for data addressed to the communication apparatus. If SOMAis used, the communication apparatus can further acquire a parameterregarding SOMA. Then, by using the acquired parameter, the communicationapparatus that receives the PPDU can separate the data multiplexed usingSOMA from other pieces of data and demodulate the separated data.

FIG. 6 is a flowchart illustrating processing realized by loading acomputer program stored in the storage unit 201 into the control unit202 and executing the program when the communication apparatus 102transmits a PPDU.

The flowchart in FIG. 6 is started when the communication apparatus 102transmits data to other communication apparatuses (e.g., to at least twoof the communication apparatuses 103 to 105). Specifically, theflowchart is started when the communication apparatus 102 receives orgenerates data to be transmitted to the other communication apparatuses.Alternatively, the flowchart may be started when the communicationapparatus 102 receives from the user an instruction to transmit dataaddressed to the other communication apparatuses to the othercommunication apparatuses.

In step S601, the communication apparatus 102 generates data which isincluded in a data field of the PPDU to be transmitted. Then, in stepS602, the communication apparatus 102 determines whether SOMA is to beused to multiplex the data generated in step S601. The determination instep S602 is made in accordance with the user's choice. If the userchooses to use SOMA to multiplex the data, the determination of thecommunication apparatus 102 is YES in step S602. If the user chooses notto use SOMA to multiplex the data, the determination of thecommunication apparatus 102 is NO in step S602. The user can choosewhether to use SOMA, after step S601 or in advance. Alternatively,whether SOMA is to be used to multiplex data may be preset in thecommunication apparatus 102.

Yet alternatively, the communication apparatus 102 may make thedetermination in step S602 according to whether the other communicationapparatuses as the destinations of the data support SOMA. Thecommunication apparatus 102 may acquire capability informationindicating whether the other communication apparatuses as thedestinations of the data support SOMA, from the other communicationapparatuses in advance or after step S601. If the other communicationapparatuses as the destinations of the data support SOMA, thedetermination of the communication apparatus 102 is YES in step S602. Ifthe other communication apparatuses do not support SOMA, thedetermination of the communication apparatus 102 is NO in step S602.

Yet alternatively, the communication apparatus 102 may make thedetermination in step S602 according to the differences of distancesbetween the communication apparatus 102 and each of other communicationapparatuses as the destinations of the data. The communication apparatus102 compares the distance between the communication apparatus 102 andthe communication apparatus 103 as the destination of the data with thedistance between the communication apparatus 102 and the communicationapparatus 104 as the destination of the data. If the difference of thedistances is greater than a predetermined threshold, the determinationis YES in step S602. If, on the other hand, the difference of thedistance between the communication apparatus 102 and the communicationapparatus 103 from the distance between the communication apparatus 102and the communication apparatus 104 is smaller than the predeterminedthreshold, the determination is NO in step S602.

If it is determined that SOMA is to be used (YES in step S602), then instep S603, the communication apparatus 102 generates a PHY preamble bysetting the value of a SOMA sub-field in an EHT-SIG field to “1”.Alternatively, the communication apparatus 102 may generate a PHYpreamble including an EHT-SIG-x field indicating a parameter regardingSOMA in addition to or instead of a SOMA sub-field. If, on the otherhand, it is determined that SOMA is not to be used (NO in step S602),then in step S604, the communication apparatus generates a PHY preambleby setting the value of a SOMA sub-field in an EHT-SIG field to “0”.Alternatively, the communication apparatus 102 may generate a PHYpreamble that does not include a SOMA sub-field and an EHT-SIG-x fieldindicating a parameter regarding SOMA.

Then, if the PHY preamble is generated in step S603 or S604, then instep S605, the communication apparatus 102 generates a wireless frameincluding the generated PHY preamble and the data generated in step S601and transmits the generated wireless frame to the other communicationapparatuses. When the communication apparatus 102 executes the processof step S605, the processing of this flow is ended.

As illustrated in FIG. 6, a communication apparatus that transmits thePPDU transmits a wireless frame including the PHY preamble indicatingwhether data has been multiplexed using SOMA, whereby a communicationapparatus that receives the PPDU can execute an appropriate receptionprocess.

The communication apparatus 102 includes an EHT-SIG-x field indicating aparameter regarding SOMA in the PHY preamble and thereby can causeanother communication apparatus that receives the PPDU to execute areception process using an appropriate parameter.

The communication apparatus 102 can indicate to a partner apparatus aparameter regarding SOMA for each PPDU to be transmitted, and thereforecan use SOMA using the appropriate parameter in response to a change ofa transmission environment in communication with the partner apparatus.The communication apparatus 102 can change a parameter to be used inSOMA according to a change in the distance from the partner apparatus.In response to an increase in the distance from the communicationapparatus 103, the communication apparatus 102 may increase thetransmission power of data to be transmitted to the communicationapparatus 103, or may change the MCS to a lower coding rate or change amodulation method in which the amount of information that can betransmitted by a single symbol (signal) is smaller. Alternatively, inresponse to a decrease in the distance from the communication apparatus103, the communication apparatus 102 may decrease the transmissionpower, or may change the MCS to a higher coding rate or change amodulation method in which the amount of information that can betransmitted by a single symbol (signal) is larger. The communicationapparatus 102 determines the distance from the communication apparatus103 based on the received signal strength indicator (RSSI) of a signalfrom the communication apparatus 103. If the RSSI of the signal receivedfrom the communication apparatus 103 has decreased, the communicationapparatus 102 determines that the distance from the communicationapparatus 103 has increased. If the RSSI has increased, on the otherhand, the communication apparatus 102 determines that the distance fromthe communication apparatus 103 has decreased. Alternatively, thecommunication apparatus 102 may change the parameter regarding SOMAaccording to a change in the error rate in communication with thepartner apparatus. If the error rate of communication with thecommunication apparatus 103 deteriorates, the communication apparatus102 may change the MCS to a lower coding rate or change the modulationmethod in which the amount of information that can be transmitted by asingle symbol (signal) is smaller. If the error rate in communicationwith the communication apparatus 103 improves, the communicationapparatus 102 may change the MCS to a higher coding rate or change themodulation method in which the amount of information that can betransmitted by a single symbol (signal) is larger. As described above,the communication apparatus 102 can set an appropriate parameterregarding SOMA in response to a change in a transmission environment incommunication with a partner apparatus.

FIG. 7 is a flowchart illustrating processing realized by loading acomputer program stored in the storage unit 201 into the control unit202 and executing the program when the communication apparatus 103receives the PPDU.

The flowchart in FIG. 7 is started when the communication apparatus 103waits for a signal from another communication apparatus. Thecommunication apparatus 103 may always wait for a signal from anothercommunication apparatus, or may repeat in a predetermined cycle theperiod in which the communication apparatus 103 communicates withanother communication apparatus and the period in which thecommunication apparatus 103 does not communicate with anothercommunication apparatus. In the period in which the communicationapparatus 103 does not communicate with another communication apparatus,the communication apparatus 103 makes power to be supplied to thecommunication unit 206 lower than in the period in which thecommunication apparatus 103 communicates with another communicationapparatus, and thereby can operate in a power-saving manner.

In step S701, the communication apparatus 103 receives the PPDU framehaving the above frame configuration from the communication apparatus102.

In step S702, the communication apparatus 103 references the SOMAsub-field in the EHT-SIG included in the PHY preamble of the PPDUreceived in step S701 and determines whether SOMA is used to multiplexthe data. If the referenced SOMA sub-field includes informationindicating that SOMA is used to multiplex the data, the determination ofthe communication apparatus 103 is YES in step S702. If, on the otherhand, the referenced SOMA sub-field does not include the informationindicating that SOMA is used to multiplex the data, the determination ofthe communication apparatus 103 is NO in step S702.

Alternatively, the communication apparatus 103 may make thedetermination in step S702 based on whether the PHY preamble of the PPDUreceived in step S701 includes an EHT-SIG-x field indicating a parameterregarding SOMA. If the received PPDU includes the EHT-SIG-x field, thedetermination of the communication apparatus 103 is YES in step S702. Ifthe received PPDU does not include the EHT-SIG-x field, thedetermination is NO in step S702.

If it is determined that SOMA is used (YES in step S702), then in stepS703, the communication apparatus 103 executes a reception process, suchas separating and demodulating data, corresponding to SOMA.

Specifically, first, the communication apparatus 103 references the IDfields in Destination_y sub-fields and identifies a Destination_ysub-field corresponding to the communication apparatus 103. Then, thecommunication apparatus 103 references the super position field in theDestination_y sub-field corresponding to the communication apparatus103. If the super position field stores a value indicating that thecombined constellation process is necessary, the communication apparatus103 executes the combined constellation process to acquire the dataaddressed to the communication apparatus 103. That is, the communicationapparatus 103 determines a combined constellation, and, based on a valuestored in the bit allocation field, acquires a bit allocated to thecommunication apparatus 103.

If, on the other hand, the value of the super position field indicatesthat the combined constellation process is not necessary, thecommunication apparatus 103 acquires the data addressed to thecommunication apparatus 103 without executing the combined constellationprocess. In this case, the communication apparatus 103 does not need toreference the bit allocation field. Alternatively, the bit allocationfield may be omitted. In this case, the communication apparatus 103 mayreference the TX power fields in the Destination_y sub-fieldscorresponding to the communication apparatus 103 and the other receptionapparatuses. Then, using the values of the TX power fields, thecommunication apparatus 103 may correct the magnitude of a signal to bereceived. Consequently, the communication apparatus 103 can demodulatethe signal with higher accuracy. In a case where the communicationapparatus 103 uses a parameter or a procedure determined in advance inthe reception process for receiving the data using SOMA, thecommunication apparatus 103 may execute the reception process forreceiving the data, without referencing the parameter included in theEHT-SIG-x field.

If the transmission power of the data addressed to the communicationapparatus 103 is smaller than the transmission power of the dataaddressed to the other communication apparatuses, the super positionfield includes information indicating that the combined constellationprocess is necessary. If, on the other hand, the transmission power ofthe data addressed to the communication apparatus 103 is larger than thetransmission power of the data addressed to the other communicationapparatuses, the super position field does not include informationindicating that the combined constellation process is necessary.

If it is determined that SOMA is not used (NO in step S702), then instep S704, the communication apparatus 103 executes a reception processfor receiving the data using a different method from SOMA to acquire thedata addressed to the communication apparatus 103. For example, thecommunication apparatus 103 executes a reception process for receivingthe data using orthogonal multiple access (OMA).

If the communication apparatus 103 performs the process of step S703 orS704, the processing of this flow is ended. Based on the data obtainedin step S703 or S704, the communication apparatus 103 can executevarious types of control such as output control (the display or theprinting of the data).

As illustrated in FIG. 7, the communication apparatus 103 can determinewhether SOMA is used to multiplex the received data by referringinformation included in the PHY frame of the received PPDU.Consequently, the communication apparatus 103 can execute an appropriatedata acquisition process (reception process) depending on whether SOMAis used to multiplex the received data.

The communication apparatus 103 receives a PHY preamble including anEHT-SIG-x field including a parameter regarding SOMA and thereby canexecute a reception process using an appropriate parameter. Since theparameter regarding SOMA is indicated for each PPDU, the communicationapparatus 103 can execute a reception process using an appropriateparameter with respect to each received PPDU. Consequently, thecommunication apparatus 102 that transmits data and the communicationapparatus 103 can execute appropriate communication adapted to a changeof a transmission path environment.

In the present exemplary embodiment, the processing in FIG. 6 isexecuted by the communication apparatus 102. The configuration, however,is not limited to this. At least a part of the processing in FIG. 6 maybe executed by the communication unit 206 (the wireless chip) that is aninformation processing apparatus included in the communication apparatus102. Similarly, in the present exemplary embodiment, the processing inFIG. 7 is executed by the communication apparatus 103. Theconfiguration, however, is not limited to this. At least a part of theprocessing in FIG. 7 may be executed by the communication unit 206 (thewireless chip) that is an information processing apparatus included inthe communication apparatus 103.

In the present exemplary embodiment, the communication apparatus 102 (anAP) transmits a PPDU, and the communication apparatus 103 (an STA)receives the PPDU. The configuration, however, is not limited to this.Alternatively, the communication apparatus 103 (the STA) may transmit aPPDU, and the communication apparatus 102 (the AP) may receive the PPDU.That is, the processing in FIG. 6 may be executed by the communicationapparatus 103, and the processing in FIG. 7 may be executed by thecommunication apparatus 102.

The PHY preamble of a predetermined wireless frame such as a beacon or aprobe response transmitted from the communication apparatus 102 (the AP)or a probe request transmitted from the communication apparatus 103 (theSTA) may not include an EHT-SIG. In this case, the PHY preamble of thepredetermined wireless frame includes legacy fields. The PHY preamble ofthe predetermined wireless frame may be configured to include an EHT-SIGbut not to include a SOMA sub-field. As described above, it may bedetermined whether to include an EHT-SIG or include a field indicatinginformation regarding SOMA according to the type of wireless frame.

At least a part or all of each of the flowchart of the communicationapparatus 102 illustrated in FIG. 6 and the flowchart of thecommunication apparatus 103 illustrated in FIG. 7 may be achieved byhardware. In a case where a part or all of each of the flowcharts isachieved by hardware, for example, a dedicated circuit may be generatedon an FPGA using a predetermined compiler according to a computerprogram for achieving the steps and used. Alternatively, a gate arraycircuit may be formed similarly to the FPGA and achieved as hardware.Yet alternatively, a part or all of each of the flowcharts may beachieved by an ASIC.

While the exemplary embodiments have been described in detail above,various embodiments of the present disclosure can employ exemplaryembodiments as, for example, a system, an apparatus, a method, aprogram, and a recording medium (a storage medium). Specifically,various embodiments may be applied to a system including a plurality ofdevices (e.g., a host computer, an interface device, an imagingapparatus, and a web application), or may be applied to an apparatusincluding a single device, for example.

Various embodiments of the present disclosure can also be achieved bythe process of supplying a program for achieving one or more functionsof the above exemplary embodiments to a system or an apparatus via anetwork or a storage medium, and causing one or more processors of acomputer of the system or the apparatus to read and execute the program.Various embodiments of the present disclosure can also be implemented bya circuit (e.g., an ASIC) for achieving the one or more functions.

According to various embodiments of the present disclosure, acommunication apparatus that communicates using SOMA communicatesinformation regarding SOMA, whereby a communication apparatus thatreceives a signal for which SOMA is used can acquire data.

Other Embodiments

Various other embodiments of the present disclosure can also be realizedby a computer of a system or apparatus that reads out and executescomputer executable instructions (e.g., one or more programs) recordedon a storage medium (which may also be referred to more fully as a‘non-transitory computer-readable storage medium’) to perform thefunctions of one or more of the above-described embodiment(s) and/orthat includes one or more circuits (e.g., application specificintegrated circuit (ASIC)) for performing the functions of one or moreof the above-described embodiment(s), and by a method performed by thecomputer of the system or apparatus by, for example, reading out andexecuting the computer executable instructions from the storage mediumto perform the functions of one or more of the above-describedembodiment(s) and/or controlling the one or more circuits to perform thefunctions of one or more of the above-described embodiment(s). Thecomputer may comprise one or more processors (e.g., central processingunit (CPU), micro processing unit (MPU)) and may include a network ofseparate computers or separate processors to read out and execute thecomputer executable instructions. The computer executable instructionsmay be provided to the computer, for example, from a network or thestorage medium. The storage medium may include, for example, one or moreof a hard disk, a random-access memory (RAM), a read only memory (ROM),a storage of distributed computing systems, an optical disk (such as acompact disc (CD), digital versatile disc (DVD), or Blu-ray Disc (BD)™),a flash memory device, a memory card, and the like.

While exemplary embodiments of the present disclosure have beendescribed, it is to be understood that the invention is not limited tothe disclosed exemplary embodiments. The scope of the following claimsis to be accorded the broadest interpretation so as to encompass allsuch modifications and equivalent structures and functions.

This application claims the benefit of Japanese Patent Application No.2019-121663, filed Jun. 28, 2019, which is hereby incorporated byreference herein in its entirety.

What is claimed is:
 1. A communication apparatus comprising: ageneration unit configured to generate an Extremely High Throughput(EHT) physical-layer protocol data unit (PPDU), wherein the generatedEHT PPDU is one of an EHT single-user (SU) PPDU, an EHT extended range(ER) SU PPDU, or an EHT multi-user (MU) PPDU, and wherein the generatedEHT PPDU includes a legacy short training field (L-STF), a legacy longtraining field (L-LTF) configured to be communicated after the L-STF, alegacy signal field (L-SIG) configured to be communicated after theL-LTF, an EHT signal field (EHT-SIG) configured to be communicated afterthe L-SIG and including a field indicating information regardingsemi-orthogonal multiple access (SOMA), an EHT short training field(EHT-STF) configured to be communicated after the EHT-SIG, and an EHTlong training field (EHT-LTF) configured to be communicated after theEHT-STF; and a transmission unit configured to transmit the PPDUgenerated by the generation unit.
 2. The communication apparatusaccording to claim 1, wherein the transmission unit includes an antennaused to transmit the EHT PPDU generated by the generation unit.
 3. Thecommunication apparatus according to claim 1, wherein in a case whereSOMA is used to multiplex data included in the generated EHT PPDU to betransmitted from the transmission unit, the generation unit generates anEHT-SIG including information regarding SOMA, and in a case where SOMAis not used to multiplex the data, the generation unit generates anEHT-SIG that does not include the information regarding SOMA.
 4. Thecommunication apparatus according to claim 1, wherein the transmissionunit transmits the generated EHT PPDU compliant with the Institute ofElectrical and Electronics Engineers (IEEE) 802.11be standard.
 5. Thecommunication apparatus according to claim 1, wherein the informationregarding SOMA is information indicating whether SOMA is used tomultiplex data included in the generated EHT PPDU.
 6. The communicationapparatus according to claim 1, wherein the information regarding SOMAis a parameter regarding SOMA used for data included in the generatedEHT PPDU.
 7. The communication apparatus according to claim 6, whereinthe parameter regarding SOMA includes at least one of informationindicating a destination of the data, information indicating amodulation method and a coding rate of the data, information regardingtransmission power of the data, or information regarding a constellationof the data.
 8. A communication apparatus comprising: a reception unitconfigured to receive an Extremely High Throughput (EHT) physical-layerprotocol data unit (PPDU), wherein the received EHT PPDU is one of anEHT single-user (SU) PPDU, an EHT extended range (ER) SU PPDU, or an EHTmulti-user (MU) PPDU, and wherein the received EHT PPDU includes alegacy short training field (L-STF), a legacy long training field(L-LTF) configured to be communicated after the L-STF, a legacy signalfield (L-SIG) configured to be communicated after the L-LTF, an EHTsignal field (EHT-SIG) configured to be communicated after the L-SIG andincluding a field indicating information regarding semi-orthogonalmultiple access (SOMA), an EHT short training field (EHT-STF) configuredto be communicated after the EHT-SIG, and an EHT long training field(EHT-LTF) configured to be communicated after the EHT-STF; and acommunication unit configured to execute communication based oninformation regarding SOMA received by the reception unit.
 9. Thecommunication apparatus according to claim 8, wherein the reception unitincludes an antenna used to receive the EHT PPDU.
 10. The communicationapparatus according to claim 8, wherein in a case where the EHT PPDUreceived by the reception unit includes the information regarding SOMA,a reception process using SOMA is performed as a reception process forreceiving data included in the received PPDU received by the receptionunit.
 11. The communication apparatus according to claim 10, wherein ina case where the EHT PPDU received by the reception unit does notinclude the information regarding SOMA, a reception process using adifferent method from SOMA is performed as a reception process forreceiving data included in the EHT PPDU received by the reception unit.12. The communication apparatus according to claim 8, wherein thereception unit receives the EHT PPDU compliant with the Institute ofElectrical and Electronics Engineers (IEEE) 802.11be standard.
 13. Thecommunication apparatus according to claim 8, wherein the informationregarding SOMA is information indicating whether SOMA is used tomultiplex data included in the received EHT PPDU.
 14. The communicationapparatus according to claim 8, wherein the information regarding SOMAis a parameter regarding SOMA used for data included in the received EHTPPDU.
 15. The communication apparatus according to claim 14, wherein theparameter regarding SOMA includes at least one of information indicatinga destination of the data, information indicating a modulation methodand a coding rate of the data, information regarding transmission powerof the data, or information regarding a constellation of the data.
 16. Acontrol method of a communication apparatus, the control methodcomprising: generating an Extremely High Throughput (EHT) physical-layerprotocol data unit (PPDU), wherein the generated EHT PPDU is one of anEHT single-user (SU) PPDU, an EHT extended range (ER) SU PPDU, or an EHTmulti-user (MU) PPDU, and wherein the generated EHT PPDU includes alegacy short training field (L-STF), a legacy long training field(L-LTF) configured to be communicated after the L-STF, a legacy signalfield (L-SIG) configured to be communicated after the L-LTF, an EHTsignal field (EHT-SIG) configured to be communicated after the L-SIG andincluding a field indicating information regarding semi-orthogonalmultiple access (SOMA), an EHT short training field (EHT-STF) configuredto be communicated after the EHT-SIG, and an EHT long training field(EHT-LTF) configured to be communicated after the EHT-STF; andtransmitting the generated PPDU.
 17. A control method of a communicationapparatus, the control method comprising: receiving an Extremely HighThroughput (EHT) physical-layer protocol data unit (PPDU), wherein thereceived EHT PPDU is one of an EHT single-user (SU) PPDU, an EHTextended range (ER) SU PPDU, or an EHT multi-user (MU) PPDU, and whereinthe received EHT PPDU includes a legacy short training field (L-STF), alegacy long training field (L-LTF) configured to be communicated afterthe L-STF, a legacy signal field (L-SIG) configured to be communicatedafter the L-LTF, an EHT signal field (EHT-SIG) configured to becommunicated after the L-SIG and including a field indicatinginformation regarding semi-orthogonal multiple access (SOMA), an EHTshort training field (EHT-STF) configured to be communicated after theEHT-SIG, and an EHT long training field (EHT-LTF) configured to becommunicated after the EHT-STF; and executing communication based onreceived information regarding SOMA.
 18. A non-transitorycomputer-readable storage medium storing a computer program for causinga computer to execute a control method of a communication apparatus, thecontrol method comprising: generating an Extremely High Throughput (EHT)physical-layer protocol data unit (PPDU), wherein the generated EHT PPDUis one of an EHT single-user (SU) PPDU, an EHT extended range (ER) SUPPDU, or an EHT multi-user (MU) PPDU, and wherein the generated EHT PPDUincludes a legacy short training field (L-STF), a legacy long trainingfield (L-LTF) configured to be communicated after the L-STF, a legacysignal field (L-SIG) configured to be communicated after the L-LTF, anEHT signal field (EHT-SIG) configured to be communicated after the L-SIGand including a field indicating information regarding semi-orthogonalmultiple access (SOMA), an EHT short training field (EHT-STF) configuredto be communicated after the EHT-SIG, and an EHT long training field(EHT-LTF) configured to be communicated after the EHT-STF; andtransmitting the generated PPDU.
 19. A non-transitory computer-readablestorage medium storing a computer program for causing a computer toexecute a control method of a communication apparatus, the controlmethod comprising: receiving an Extremely High Throughput (EHT)physical-layer protocol data unit (PPDU), wherein the received EHT PPDUis one of an EHT single-user (SU) PPDU, an EHT extended range (ER) SUPPDU, or an EHT multi-user (MU) PPDU, and wherein the received EHT PPDUincludes a legacy short training field (L-STF), a legacy long trainingfield (L-LTF) configured to be communicated after the L-STF, a legacysignal field (L-SIG) configured to be communicated after the L-LTF, anEHT signal field (EHT-SIG) configured to be communicated after the L-SIGand including a field indicating information regarding semi-orthogonalmultiple access (SOMA), an EHT short training field (EHT-STF) configuredto be communicated after the EHT-SIG, and an EHT long training field(EHT-LTF) configured to be communicated after the EHT-STF; and executingcommunication based on received information regarding SOMA.